Russia has accused Turkey of shooting down its warplane near the border with Syria in order to protect its oil trade with the Islamic State (IS) group, BBC News reports.

Speaking at international talks on climate change in Paris, Russian President Vladimir Putin called the downing of the plane a "huge mistake".

Turkey has denied any ties to IS and is part of a US-led coalition carrying out air strikes against the militant group. The Turkish government has refused to apologize for the incident.

Russia has imposed sanctions on Turkey over the downing of the plane, including restrictions on imports of Turkish food and an end to visa-free travel.

IS earns much of its money from illegal sales of oil - however, Turkey has staunchly denied that it is involved in the trade.

"We have every reason to think that the decision to shoot down our plane was dictated by the desire to protect the oil supply lines to Turkish territory," Putin said at a news conference in Paris on Monday, November 30, according to BBC.

He said Russia had received more information to show that IS oil was passing through Turkish territory.